Compiling against typescript language service

I'm trying to figure out the API for TypeScript language service, so created a project in VS and included relevant files from /compiler and /services folders.

The only problem is that compiling that project every time takes a bit of time, even though I don't intend to modify the TypeScript code itself, and thus don't need to recompile it over an over again.

So far I've come up with the solution of generating typescript.d.ts with the declarations, and using *.js at runtime. Is that the best way? Is that the intended way? Is that how you do it at Microsoft?